Acoustical devices



Nov. 15, 1960 w. w. HAERTHER, JR 2,960,177

ACOUSTICAL DEVICES Filed Nov. 25, 195'! INVENTOR.

ACOUSTICAL DEVICES William W. Haerther, Jr., Geneva, Ill. assignor to Hawley Products Company, St. Charles, Ill., :1 corporation of Delaware Filed Nov. 25, 1957, Ser. No. 698,824

11 Claims. (Cl. 181-32) This invention relates in general to acoustical devices and, more particularly, to improved types of sound reproducing diaphragms.

It is a primary object of this invention to enable a novel sound producer or reproducer to be afforded, which will have a substantially even response curve, where all sounds of the audible range will be produced or reproduced with substantially equal efficiency.

Another object of this invention is to provide a novel diaphragm capable of reproducing both high and low frequency notes corresponding in intensity, timbre mellowness, and other qualities with the originally produced sound waves.

Acoustic diaphragrns of rectangular shape lend themselves to mounting in certain locations, such as, for example, under the dashboard of automobiles, and the like, much better than diaphragms of other shapes such as,

for example, pyramidal-shaped diaphragms or coneshaped diaphragms. However, the problem, of affording an effective rectangular-shaped diaphragm having good sound reproducing qualities has long bothered those skilled in the art. It has been found that the problems increased as the ratio of the length of the diaphragm to the width thereof increased. One such problem has been that, when the aforementioned ratio of length to width exceeded two to one, the ends of the diaphragm tended to flap, thus distorting the sounds reproduced by the diaphragm. ening ribs did not adequately solve this problem.

An important object of this invention is to enable a novel, effective sound reproducing diaphragm having a rectangular shape to be afforded.

Another object of the present invention is to enable a novel, elfective acoustic diaphragm, having good sound reproducing characteristics, to be afforded with a ratio of length to width of at least eight and one-half to one and one-half.

Another object is to provide a novel rectangularshaped diaphragm having a vibratile portion embodying a novel rib construction.

Another object is to afford a novel diaphragm having a vibratile portion embodying a substantially ellipticalshaped concave central portion.

A further object of the present invention is to aiford a novel rectangular, sound reproducing diaphragm, the parts of which are constituted and arranged in a novel and expeditious manner.

Yet another object of the invention is to enable a novel rectangular, sound-reproducing diaphragm having the aforementioned characteristics to be afforded which is thin and light in weight.

Another object is to enable a novel and practical diaphragm of substantially rectangular shape to be afforded,

It has been found that mere simple strengthwhich has a large frontal area and reproducing characteristics.

A further object of the present invention is to afford a novel diaphragm of the aforementioned type wherein the vibratile portion thereof is effectively responsive, as a unit, to both high and low frequency vibrations.

Other and further objects of the present invention will be apparent from the following description and claims are illustrated in the accompanying drawings which by way of illustration show a preferred embodiment of the present invention and the principles thereof, and what is now considered to be the best mode in which it is contemplated to apply these principles. Other embodiments of the invention embodying the same or equivalent principles may be used, and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. l is a rear elevational View of a diaphragm embody-ing the principles of the present invention;

Fig. 2 is a longitudinal sectional view taken substantially along the line 2-2 in Fig. 1;

Fig. 3 is a transverse sectional view taken substantially along the line 3-3 in Fig. 1;

Fig. 4 is an enlarged detail sectional view taken substantially along the line 44 in Fig. l;

Fig. 5 is a transverse sectional view taken substantially along the line 5--5 in Fig. 1;

Fig. 6 is a rear elevational view similar to Fig. l, but showing a modified form of the present invention; and

Fig. 7 is a detail sectional view taken substantially on the plane 7-7 indicated in Fig. 6.

A diaphragm 1, embodying the principles of the present invention, is shown in Figs. 1 to 5 of the drawings to illustrate one form of diaphragm contemplated by the invention.

In general, the diaphragm 1 embodies a concave vibratile portion 2 connected by an undulated portion 3 to a substantially rectangular-shaped supporting flange member or rim 4, adapted to be clamped between the supporting braces, or the like, of a speaker.

One aspect of the invention is that it enables 'a polyg- :onal-shaped diaphragm, such as, for example, the rectangular-shaped diaphragms shown in the drawings, and which will be discussed in greater detail hereinafter, to be constructed in a novel and expeditious manner whereby a concave vibratile portion may be afforded which embodies a compound-curve construction, including a concave, substantially elliptical-shaped central portion, and shallower outer portions.

The vibratile portion 2 is of a convex-rearwardly shape, flaring generally outwardly and forwardly from a tubular-shaped nipple 5 at the centrally located apex thereof to a substantially rectangular-shaped base 6, having two parallel short ends 7 and 8, connected by two parallel longitudinally extending sides 9 and 10, disposed substantially perpendicular to the ends 7 and 8, Figs. 1, 2 and 3.

The diaphragm 1 is of one-piece construction, and may be made of any suitable material such as, for example, accreted fibrous material.

The vibratile portion 2 of the diaphragm l. embodies a substantially elliptical-shaped, convex-rearwardly central portion 11, which slopes outwardly and forwardly from the centrally disposed tubular portion 5.

The major axis of the elliptical central portion 11 is disposed on the longitudinal center line of the vibratile portion 2, and the opposite ends of the elliptical portion 11 form the inner end portions of the main branches 12 and 13 of two forked ribs 14 and 15, respectively, which constitute a part of the vibratileportion 2. The ribs 14 provides good soundand 15 are an integral part of the vibratile portion 2, and are preferably of the same thickness as the remaining portions of the vibratile portion 2. They are so constituted and arranged that, in operation, the vibratile portion 2 tends to vibrate as a unit throughout its length and breadth.

;The main branches 12 and 13 of the forked ribs 14 and 15 extend in opposite directions from the tubular portion 5, longitudinally of the vibratile portion 2, and terminate at their free end portions in spaced relation to the ends 7 and 8, respectively, of the vibratile portion 2, Figs. 1 -and'2. They are generally of convex-rearwardly shape,

although the convex rearward shape thereof is partially "interrupted at the outer ends of the elliptical body portion 11 by indentations 16 and 17, which reduces the depth of the main branches 12 and 13 at those points,

tively, of the vibratile portion 2 in inwardly spaced relation to the outer ends of end branches 18 and 19, Fig. l.

The other forked rib 15 is identical in construction to the forked rib 14, except that it is a mirror image thereof. It embodies the main branch 13, two end branches 24 and 25, and two intermediate branches 26 and '27. The end branches 24 and 25 fork outwardly away from each other from the free end portion of the main branch 13, and terminate at their outer ends at the corners 2 8 and 29, respectively, of the vibratile portion 2 at the opposite ends of the end. The intermediate branches 26 and 27 fork outwardly away from each other from opposite sides of the indentation 17, and terminate at their outerends at the sides 9 and 10, respectively, of the vibratile portion 2 in inwardly spaced relation to the outer ends of the end branches 24 and 25, Fig. '1. V

It will be seen that when the diaphragm 1 is so constructed, the walls thereof are relatively thin, and the vibratile portion 2 thereof is of a generally convex-rearwardly shape, with three rearwardly projecting humps "aflforded therein, two of the humps being afforded at the free ends of the main branches 12 and 13 of the forked ribs 14 and 15, respectively, and the third hump being afforded by the centrally disposed elliptical portion 11 of the vibratile portion 2.

As may be seen in Figs. 2, 3 and 5, the rearward depth of the diaphragm 1 is greatest at the apical center thereof, with the ribs 14 and 15 diminishing in depth toward the ends 7 and 8, respectively, but the entire vibratile portion is of curved form with the ribs 14 and 15 affording a compound curve construction therefor. It has been found that with vibratile portions of speakers having the compound curve construction of this invention, good sound reproducing characteristics are afforded in rectangular diaphragms having a length and width ratio of eight and one-half to one and one-half.

It has been found that with the forked-rib construction of the vibratile portion 2 of the diaphragm 1, the structural strength of the vibratile portion 2 is so dis tributed that the latter portion tends to vibrate substantially as a unit on the undulated portion 3 by which it is connected to the flange 4 when driven by a suitable member such as, for example, the voice coil of a dynamic speaker mounted on the nipple of the diapbragm 1.

In the formation of the diaphragm 1, the tubularshaped nipple 5 is normally formed with a cap portion 30 closing the rear end thereof, and this cap portion 30 may be clipped or otherwise removed therefrom prior to mounting the diaphragm 1 in a suitable speaker or the like.

Four openings 31 are formed in the outer edge portion of the undulating portion 3 and the inner edge portion of the flange 4, adjacent to, but in outwardly spaced relation to the corners 20, 21, 28 and 29, respectively, of the vibratile portion 2, Figs. 1 and 4, for a purpose which will be discussed in greater detail presently.

Two common disadvantages of rectangular-shaped acoustical diaphragms heretofore known in the art have been that quality of sound reproduction has been poor, and that the diaphragm tended to crack and break out at the corners. It has been found that with acoustical diaphragms constructed in the manner of the diaphragm 1, sound reproduction of good quality is afforded and the tendency of the corners to crack is alleviated. It is believed that the affording of openings such as the openings 31 in the corners of the diaphragm 1 are important factors in the improvement in both of these characteristics. It is believed that the end portions and longitudinal side portions of rectangular-shaped diaphragms tend to vibrate relative to each other, thus tend= ing to distort the reproduction of sounds and to flex, and eventually tear or break, the junction between the two portions, whereas, with diaphragms embodying openings, such as the openings 31, the adjacent end and side portions are permitted to flex and vibrate as a unit to thereby improve the tone reproducing qualities and effectively reduce the tendency of the diaphragms to tear at the corners.

In the operation of the diaphragm 1, the flange 4 may be suitably clamped between supporting braces, or the like, in a speaker, with the vibratile portion 2 movably supported on the flange 4'by the undulated portion 3, and "with the voice coil of the speaker mounted on the tubular member 5. It has been found that, with the diaphragm 1 so mounted in a speaker, remarkably true reproduc tion of sounds is afforded thereby.

In Figs. 6 and 7 of the drawings, a diaphragm 32 is shown to illustrate a modified form of the present inven tion. Like the diaphragm 1 shown in Figs. 1 to 5, inclusive, the diaphragm 32 embodies a substantially elliptical shaped central portion 33 surrounding a tubular, apical portion 34, and two forked ribs 35 and 36. The forked rib 35 embodies a main branch 37, two end branches 38 and 39 and two intermediate branches 40 and 41, which are positioned similarly to the branches 12, 18, 19, 22 and 23, respectively, of the diaphragm 1. The forked rib 36 also embodies a main branch 42, two end branches 43 and 44, and two intermediate branches 45 and 46, and these branches are positioned similarly to the branches 13, and 24--27, respectively, of the diaphragm 1.

One of the principal differences between the diaphragms 1 and 32 is that, in the diaphragm 32, the main branches 37 and 42 are continuously convex-rearwardly in form, the opposite end portions of the elliptical central portion 33 being longer than the end portions of the central portion 11 of the diaphragm 1, and extending the entire length of the main branches 37 and 42, respectively.

With this latter construction, the diaphragm'32 has the advantage of a compound-curve construction generally like that of the diaphragm shown in Figs. 1 to 5, inclusive, but without the three longitudinally spaced humps or pockets of the diaphragm 1, the elliptical central portion 33 and the ribs 35 and 36 of the diaphragm 32 affording a more nearly unitary concavity, which diminishes in depth relatively gradually from the tubular member 34 toward both ends of the vibratile portion 47, Fig. 7.

Another difference between the diaphragm 32 and the diaphragm 1 is that the undulated portion 48 of the diaphragm 32 has a single undulation, Fig. 7, whereas the undulated portion 3 of the diaphragm 1 is of a double e e se bend yp having t o undulations, Fig. 2. However, it will be appreciated by those skilled in the art that either type of undulated portion may be used in the practice of my invention without departing from the purview thereof.

Acoustical diaphragms of substantially rectangular shape have a number of advantages over diaphragms of other shapes such as, for example, conical shaped diaphragms. For example, diaphragms of rectangular shape readily lend themselves to mounting behind dashboards of automobiles, and the like. By the practice of this invention, a rectangular-shaped diaphragm having good structural strength and having good sound producing or reproducing qualities may be readily constructed. It will be seen that by the practice of this invention a rectangular-shaped diaphragm having a relatively large frontal area may be afforded, and it has been found that with this construction the vibratile portion vibrates substantially as a unit at frequencies in the audible range, and affords remarkably true reproductions of the originally produced sound waves in such a range.

Thus, while the preferred embodiments of the present invention have been illustrated and described herein, it is to be understood that these are capable of modification and variation without departing from the purview of the following claims.

The invention is hereby claimed as follows:

1. A rectangular dynamic acoustic diaphragm comprising an elongated vibratile portion having a tubular apical portion, and means extending around said vibratile portion and attached thereto in supporting relation to the latter, said vibratile portion having two forked-rib portions formed therein and extending in opposite directions to each other from said apical portion longitudinally of said vibratile portion, said rib portions each having a main branch having a free end portion, two end branches flaring outwardly away from each other at said free end portion, and two other branches flaring outwardly in opposite directions from a longitudinal central portion of said main branch.

2. A diaphragm as defined in claim 1 and in which each of said main branches has two convex-rearwardly end portions separated by a concave-rearwardly intermediate portion.

3. A diaphragm as defined in claim 1 and in which each of said main branches is continuously convex-rearwardly.

4. An acoustic diaphragm comprising an elongated vibratile portion having front and rear faces, said portion being generally convex-rearwardly and having two convex-rearwardly forked ribs extending in opposite directions to each other longitudinally of said portion, each of said forked ribs having a main body portion extending along the longitudinal center line of said vibratile portion and means disposed outwardly of said portion and integral therewith for flexibly supporting said vibratile portion relative thereto.

5. An acoustic diaphragm comprising a rectangularshaped vibratile portion, of substantially uniform wall thickness throughout, said portion having an elongated rib extending longitudinally thereof, an undulated portion extending around and projecting outwardly from said vibratile portion, and a flange extending around and projecting outwardly from said undulated portion in position to suspendingly support said vibratile portion and said undulated portion, said undulated portion and said flange having openings therethrough in outwardly disposed relation to respective ones of the outer corners of said vibratile portion.

6. An acoustic diaphragm comprising a rectangularshaped elongated vibratile portion, of substantially uniform wall thickness throughout, said portion having an elongated rib extending longitudinally thereof, an undated portion extending around and projecting outwardly from said vibratile portion, and a flange extending around and projecting outwardly from said undulated portion in position to suspendingly support said vibratile portion and said undulated portion, said undulated portion and said flange having four openings therein, each of said openings extending through a portion of said undulated portion and a portion of said flange inwardly of the outer edge of said flange, and adjacent to and outwardly of a respective one of the outer corners of said vibratile portion.

7. An acoustic diaphragm comprising an elongated vibratile portion having a front and rear face, said portion being generally convex rearwardly and having a substantially centrally disposed apical portion, and two elongated convex rearwardly forked ribs extending in opposite directions to each other from said apical portion longitudinally of said vibratile portion, said apical portion and said ribs being disposed in such position on said vibratile portion as to afford three rearwardly-convex humps spaced from each other longitudinally of said vibratile portion, and means extending around said vibratile portion for flexibly supporting the latter.

8. An acoustic diaphragm comprising an elongated vibratile portion having a front and rear face, said portion being generally convex rearwardly and having a substantially centrally disposed apical portion, and two elongated convex rearwardly forked ribs extending in opposite directions to each other from said apical portion longitudinally of said vibratile portion, said apical portion and said ribs being disposed in such position on said vibratile portion as to afford three aligned rearwardly-convex humps spaced from each other longitudinally of said vibratile portion, the central one of said humps being of greater height than the other two humps, and means disposed around said vibratile portion and attached thereto in position to support the latter.

9. An acoustic diaphragm comprising an elongated vibratile portion having a front and rear face, said portion being generally convex-rearwardly and having a substantially centrally disposed apical portion, and two elongated convex-rearwardly forked ribs extending in opposite directions to each other from said apical portion longitudinally of said vibratile portion, each of said forked ribs having one end terminate at said apical portion, and a forked end having two branches, each of the branches terminating at a respective side of one end of said vibratile portion, each of said ribs also having two other branches disposed between said one end and said forked end, said other branches terminating at one end at a respective longitudinal side of said vibratile portion, and means, including an undulated member, extending around and attached to said vibratile portion in position to flexibly support the latter.

10. An acoustic diaphragm as defined in claim 9, and in which said vibratile portion is substantially rectangular in shape and has four outer corners, and in which said undulated portion has four openings extending through the outer edge portion thereof in outwardly disposed relation to respective ones of said corners.

11. An elongated acoustic diaphragm comprising a onepiece concave vibratile portion, and undulating supporting means projecting outwardly from said vibratile portion, said vibratile portion having a centrally disposed substantially elliptical-shaped concave portion, and shallower concave portions disposed outwardly of said ellipticalshaped portion longitudinally of said last mentioned portion, said shallower concave portions being deeper than the portions of said elliptical-shaped portion immediately adjacent thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,328 Tichenor et a1 Oct. 10, 1933 2,020,705 Stenger Nov. 12, 1935 2,662,606 Hurley Dec. 15, 1953 2,685,935 Lenz Aug. 10, 1954 2,820,527 Bobb et al Jan. 21, 1958 UNITED STATES PATENT OFFICE EEliTlFlCATlON OF CORRECTWN PatentNo.a 2 960 177 November 155 1960 William W Haerthe-r JIM,

It is hereby certified that en appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected belowo Column 3, line 38, after "end" insert 8 column 5 line 72 for "undated" read undulated e Signed and sealed this 23rd day of May 1961o (SEAL) Attest:

ERNEST W. SWIDER DAVID L. "LADD Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE Q'lilQA'ilON l CRECTWN Patent-N0a 2 960 177 November 15 1960 William Wo Haerther, Jra

It is hereby certified that en .ippears in the above numbered pai ent requiring correction and that the said Letters Patent should read as corrected belowc Column 3, line 38 after "end" insert 8 column 5 line 72 for "undated read undulated ==a Signed and sealed this 23rd day of May 1961a (SEAL) Attest:

ERNEST W. SWIDER DAVID L. 'LADD Attesting Officer Commissioner of Paten 

